Housings for venetian blind tilter mechanisms have been used in the past where the housings comprise two or more metal stampings held together by bendable tabs or other mechanical means. The walls of these housings have included apertures for forming journal bearings to support meshing worm gears and worm wheels contained within the housings. A problem existing with metal housings made of a number of parts has been the difficulty in maintaining and assuring precise alignment of the apertures forming the journal bearings supporting the worm wheel and worm gear. Any misalignment of the apertures results in binding of the worm gear and worm wheel increasing the force necessary to tilt the venetian blind assembly, or even in some instances, preventing such tilting. An attempt has been made to correct this alignment problem by maintaining strict manufacturing and assembly tolerances but this has necessarily resulted in increased costs.
Further cracks or spacings between the parts can allow dust or dirt to enter into the housing which can further increase the forces necessary to operate a tilting mechanism.
Stamped metal housings comprising a number of separate parts, besides having the aforementioned liabilities, also are subjected to a considerable assembly expense simply because of the operations involved in assembling and fastening separate parts together.
A further problem with conventional tilter housings having worm gears and worm wheels is that the tilter mechanism may be damaged if excessive force is applied to the mechanism in an attempt to tilt the slats of a blind beyond a limit point or if for some reason the slats become jammed and are prevented from tilting.
It is therefore an object of my invention to provide for a tilter housing which may be inexpensively manufactured while at the same time providing a structure allowing easy assembly of gearing within the housing and wherein the gearing will be in proper alignment without entailing undue quality control procedures.
It is therefore a further object of my invention to provide for a tilter housing having a slip clutch type of connection between the worm wheel and worm gear to prevent excessive forces being applied to the tilter mechanism.